Means for swinging freely suspended roller assemblies



Oct. 3, 1961 R. F. LO PRESTI 3,002,606 MEANS FOR SWINGING FREELY SUSPENDED ROLLER ASSEMBLIES Filed June 4. 1959 I INVENTOR. Roy E La-Presti BY lffOP/VJVS.

3,002,005 Patented Oct. 3, 1961 3,002,606 MEANS FOR SWINGING FREELY SUSPENDED ROLLER ASSEMBLIES Roy F. Lo Presti, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Filed June 4, 1959, Ser. No. 818,214 9 Claims. (Cl. 198-202) This invention relates generally to belt conveyors and particularly to means for automatically repositioning belt training rollers upon reversal of belt travel.

In belt conveyors of the type illlustrated in the Craggs et a1. Patent No. 2,773,257, the carrying run of a flexible conveyor belt is supported on a plurality of troughing roller assemblies suspended at spaced intervals from wire ropes. The ropes in turn are supported by generally equidistantly spaced stands. The return run of the belt is supported on return roller assemblies which are spaced substantially further apart than the troughing roller assemblies.

Maintaining the belt centered or trained on the roller assemblies is a problem, particularly when the belt is running empty. If a belt detrains while carrying a load, the carrying capacity is reduced since the optimum troughing contour is disrupted. The load may even drop off. When the belt runs empty, detraining causes excessive wear on the belt edges and sets up disruptive strains in the conveyor system.

Various expedients to overcome belt detraining have been proposed. One highly successful method is to mount the rollers, particularly the wing rollers of a three roller troughing assembly, for limited swinging movement about their inner ends whereby the roller may be canted in the direction of belt travel. A good example of this is illustrated in pendingapplication Serial No. 704,483, now abandoned, entitled Troughing Roller Assembly for Belt Conveyor. The rollers exert a training effect as the belt passes over them which is perpendicular to the longitudinal axis of the roller. By canting the wing rollers in the direction of belt travel, the training force exerted on the belt is thereby directed inwardly. Since the amount of training effect is proportional to the amount of contact between'belt and roller, any creep of the belt up one roller and down the opposite will increase the training effect upon that roller which makes greater contact with the belt. This is an automatic training system.

Return rollers are often mounted for a limited swinging movement so that they will follow the direction of belt travel and orient themselves downstream. By maintaining their ends relatively free to swing, any detraining of the belt to one side will automatically cant the roller to a training position.

Frictional contact between belt and roller is often used to swing the roller into training position. The swinging action is often quite slow however. In some instances, particularly when the belt is running empty, the inertialforces between the swinging end of the roller and its sliding surface are greater than the drag between the belt and roller. In this situation the rollers will not shift until a belt seam passes over the roller and imparts a jolt in the direction of belt travel, suflicient to overcome the inertial forces. With a belt having long stretches between adjacent seams, many hundreds of feet may have to pass over the roller before it is repositioned.

Accordingly, a primary object of this invention is to provide a training roller assembly which is substantially instantly responsive to reversal of belt travel to reorient the roller in a training position.

Another object is to provide a belt training roller assembly wherein the belt imparts a series of jolts to the roller assembly to relocate it automatically in response to reversal of belt travel.

Another object is to provide in a troughing idler assembly having wing rollers pivoted about their inner ends and free to swing into a training position at their outer ends means for instantly swinging the rollers upon reversal of belt travel.

A further object is to provide a relatively freely suspended return roller assembly which is instantly swung into a belt training position upon reversal of the direction of belt travel by the movement of the belt over the assembly.

Other objects and advantages of the invention will become apparent from time to time throughout the course of the following specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings in which:

FIGURE 1 is a section through a flexible strand conveyor illustrating two forms of training roller suspension;

FIGURE 2 is a section taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a partial plan view taken along the line 33 of FIGURE 1; and

FIGURE 4 is a partial plan view with parts broken away of the right wing roller assembly of FIGURE 1.

Like reference numerals will be used to indicate like parts throughout the following specification and drawings.

A section through a flexible strand belt conveyor of the type illustrated in the Craggs et al. Patent No.

'- tion of belt travel. Right wing roller 123 is mounted for 2,773,257 is illustrated in FIGURE 1. A pair of flexible strands and 111 are seated in horizontal saddle members 112 and 113 which are welded to upper sleeves 114 and 115 of a pair of supporting stands. The upper sleeves are telescopically received on bottom sleeves 116 and 117 connected to feet 118 and 119 resting on the ground 120. Any suitable means such as a set screw (not shown) may be used to adjust the sleeves so as to orient the saddles 112, 113 in the same horizontal plane. Strut 121 maintains the stands a substantially fixed distance apart.

A troughing roller assembly including wing rollers 122, 123 and a center primary load carrying roller 124 supports the carrying reach 125 of a flexible belt from the flexible strands.

The suspension assembly for right wing roller 123 is illustrated in FIGURE 4. The left wing roller suspension assembly is substantially the same and has not been illustrated.

(Shaft 126 of center roller 124 is pivotally connected as at 127 to a pair of cars 128 extending inwardly from mounting plate 129. The mounting plate is connected by a pair of outwardly diverging braces 131, 132 to a curved end plate 130. Right wing roller 123 is pivotally mounted as at 133 at its inner end to the mounting plate 129. The roller rotates freely on dead shaft 134 which slides in a groove or slideway 135 in the end plate. In this instance the groove is slotted as at 136 to permit insertion or removal of shaft 134. The slideway could be formed as an elongated closed aperture or merely as an open recess. End plate is welded to a -U-shaped flexible strand connector 137. Wedge 138 seats the strand snugly in the connector.

Center roller 124 is thereby free to flex in a substantially vertical plane generally perpendicular to the direcpivotal movement about its inner end in a plane generally parallel to that portion of the belt in contact with it, but is not flexible in a vertical plane.

Projections or bumps 140, 141 are formed on the surface of the wing rollers near their outer ends. These bumps raise and drop the belt as it passes over them which imparts a series of jolts to the roller. The jolts cause the free swinging end of the roller to move along slideway 135 so as to cant the wing roller in the direction of belt travel. The bumps may be either continuous or discontinuous along the length of the wing rollers but in any event are discontinuous peripherally of the roller. In this instance the distance between the inner ends 142 and 143 of the bumps is only slightly greater than the span of the belt when it runs in a centered position. The actual size of the bump may be varied within wide limits.

A return roller 150 is swingably connected to the supporting stands by lost motion linkage assemblies indicated generally at 151 and 152. The assemblies are substantially identical and a description of one will describe the other.

Lost motion linkage assembly 151 includes a sleeve 153 telescopically received over sleeve 116 of the support stand. A link 154 having a slot 155 is welded to the base of sleeve 153 for pivotal movement about the support stand. Collar 156 and set screw 156a form a base upon which the link 154 rotates.

Roller shaft 157 is rotatably journaled in bearing block 158 which is pivotally carried by pin 159 slidable in slot 155. Side guide roller 160 is rotatably mounted on roller pin 161 journaled in bearing block 158.

Return roller 150 supports the return reach 165 of the belt. A projection 166 similar to projections 140, 141 on the wing rollers extends, in this instance, substantially the entire length of the return roller. It may be formed by a strip of material fastened to the roller, or a weld bead deposited on it, as shown in FIGURE 2, but like bumps 140, 141 extends only a small fraction of the peripheral distance about the roller.

The use and operation of the invention is as follows:

The conveying reach of the belt is shown running centered in FIGURES l and 4, and in the direction of the solid arrow in FIGURE 4. Wing rollers 122 and 123 are canted in the direction of belt travel, as shown in the solid line position of FIGURE 4, so the training effect exerted on the belt will be directed inwardly. For purposes of illustration it may be assumed that the training effect between a roller and belt acts perpendicularly to the longitudinal axis of the roller. So long as the belt runs in the direction of the arrow of FIGURE 4, it will tend to stay centered because as it detrains to one side, the training effect of the roller up which the belt creeps will increase whereas the training effect of the roller down which the belt moves will decrease. Since the amount of training effect is roughly proportional to the lengths of contact between the belt and roller, the unbalanced training effect will cause the belt to move back to a centered position.

If right wing roller 123 were to stay in the solid line position of FIGURE 4 when the direction of belt travel is reversed as indicated as indicated by the dotted arrow in FIGURE 4, the roller would cause the belt to detrain and run wild up the roller. To avoid this condition, the roller is pivotally mounted about its inner end at 133 so that it may assume the dotted line position of FIGURE 4. The roller will not move to its dotted line position however if the drag of the belt on the roller is less than the retarding drag of the roller shaft 134 in end plate 130.

Projections 140 and 141 quickly reorient the roller by overcoming the inertial forces between the shaft and end plate. As the belt passes over the bump, in this instance once per revolution of the roller, it will be quickly lifted and then just as quickly dropped. The effect is a series of jolts or impulses which inch the roller into the dotted line training position for reversed belt travel. By locating the projections outside the normal span of the belt when the belt runs centered, any slapping noise created by the belt passing over the roller is eliminated except during the time,

in which the roller is being reoriented. It would of course be feasible to extend the projections the complete length of the roller and they may be located in any particular spot. Similarly, a plurality of projections spaced equidistantly or randomly about the periphery may be used but in any event they must be discontinuous about the periphery to give the jolting effect.

The particular wing roller mounting structure illustrated is only exemplary. End plate need not be curved for example, and various other end suspensions of roller shaft 134 may be utilized. For example, it is entirely within the scope of the invention to utilize a semicradled swinging wing roller which is connected to end plate 130 by a link.

The operation of return roller is analogous to that of the wing rollers. With this particular suspension, which again is exemplary,the return roller will always be swung about the pivot posts 116 and 117 downstream in the direction of belt travel. If the belt tends to detrain to one side, the lost motion linkage connection including slot and pivot pin 159 will cant the roller to a training position.

The return roller may not immediately assume the new downstream position upon reversal of belt travel due to friction between link 154 and collar 156 and between slot 155 and pin 159. The bump or projection 166 then imparts a series of jolts which swing the links about the post 116 to the dotted line position of FIGURE 3. End guide rollers 160, 162 prevent the belt from passing more than a short distance past the roller ends.

Actual tests have demonstrated the efficiency of the bumps in both conveying and return roller assemblies. Without projections, several hundred feet of the belt must pass over the rollers before they are reoriented to a training position, whereas the bumps cause the rollers to reorient in a matter of ten to twelve feet.

The foregoing description is illustrative only and not definitive. Accordingly, the invention should not be limited except by the scope of the following appended claims.

I claim:

1. In a belt conveyor troughing roller assembly having at least a primary load carrying roller flanked by a pair of wing rollers, each wing roller having its outer end mounted for swinging movement to and fro about its inner end as a pivot whereby the wing rollers may be canted in the direction of belt travel, means for canting the roller in the direction of belt travel, said canting means including a peripherally discontinuous projection on the surface of a wing roller, said projections causing the belt to impart a jolt to the roller as it passes thereover.

2. The structure of claim 1 wherein the projections extend along the length of the roller.

3. In a belt conveyor troughing roller assembly having at least a primary load carrying roller flanked by a pair of wing rollers, each wing roller having its outer end mounted for swinging movement to and fro about its inner end as a pivot whereby the wing rollers may be canted in the direction of belt travel, means for canting the roller in the direction of belt travel, said canting means including a peripherally discontinuous projection on the surface of a wing roller, said projections causing the belt to impart a jolt to the roller as it passes thereover, said projections being located near the outer ends of the rollers, the inner ends of the projections being spaced apart a distance slightly longer than the span of the belt in a centered condition.

4. In a return roller for a belt conveyor, said return roller being mounted for swinging movement to and fro in the direction of belt travel and having its ends maintained a substantially fixed distance apart, means for moving the roller in the direction of belt travel, said means comprising a peripherally discontinous projection on the roller engageable with the belt at least once per revolution of the roller for quickly lifting and dropping the belt as it passes over the projections to thereby impart successive positioning jolts to the rollers.

5. The structure of claim 4 wherein the projections have a substantially uniform height throughout their length.

6. A belt training roller assembly for a belt conveyor, said assembly including a center primary training roller, a pair of wing rollers having their inner ends mounted for troughing movement with the center roller and their outer ends mounted for at least limited swinging movement in the directions of belt travel about their inner ends, means for connecting the roller assembly to supporting structure, and means for can-ting the wing rollers in the direction of belt travel, said canting means including a peripherally discontinuous projection on the surface of each roller for lifting and dropping the belt as it passes over the projections to thereby impart successive positioning jolts to the rollers.

7. The belt training roller assembly of claim 6 further characterized in that the projections are located near the outer ends of the wing rollers, the inner ends of the projections being spaced apart a distance slightly longer than the span of belt in a centered position.

8. A belt training roller assembly for a belt conveyor, including a center primary training roller, a pair of mounting plates, the center roller being mounted on the plates for flexnre in a substantially vertical plane, means for connecting the plates and center roller to a support structure whereby displacement of the center roller with respect to the support structure in a direction substantially parallel to belt travel is prevented, a pair of wing rollers having their inner ends connected to the mounting plates and their outer ends free to swing in a direction substantially parallel to belt travel about their inner ends as a pivot, and means for canting the wing rollers in the direction of belt travel, said canting means including a peripherally discontinuous projection on the surface of each roller for lifting and dropping the belt as it passes thereover to impart successive positioning jolts to the rollers.

9. A belt training roller assembly for use in a belt conveyor, said roller assembly including a roller, means for enabling at least one end of the roller to swing in the direction of belt travel to thereby enable the roller to impart a training eflect to the belt, and means for moving the roller into a training position automatically upon reversal of direction of belt travel, said roller moving means including a discontinuous peripheral projection on the surface of the roller which quickly lifts and drops the belt as it passes thereover whereby successive positioning jolts are imparted to the roller.

References Cited in the file of this patent UNITED STATES PATENTS 

